US2008/0217254 (PTL 1) discloses the background art of the technical field of this invention. The document discloses “an automated device including a rotary microparticles (magnetic beads) trapping unit which is disposed on a capillary flow path, and a high speed liquid chromatograph-tandem mass spectrometer, in which the microparticles trapping unit complements and washes a complex obtained by the bonding of microparticles previously bonded with an antibody and a substance being measured, and elutes the substance being measured from the microparticles, and a method thereof”. JP-A-1-187459 also discloses the background art of the technical field of this invention. The document discloses “an immunological analysis method of allowing an antigen-antibody reaction in a reaction solid phase to isolate a complex obtained by the bonding of microparticles previously bonded with an antibody and a substance being measured due to the antigen-antibody reaction from the reaction solid phase, performing measurement using the spectroscopy, and quantifying a target component”.